Green’s Dictionary of Slang

a dedicatedly masculine man, whose lack of sensitivity/intelligence is more than compensated for by his enthusiasm for all forms of sport; also attrib.

1959		C. MacInnes Absolute Beginners 132: These hefty rugger-b—r types are so damn boyish, and beneath their thick heads, such bullies.
1989		J. Hobbs Thoughts in a Makeshift Mortuary 145: The student body divided [...] into four factions: the studious, the rugger buggers, the social set and the lefties.
1998		K. Sampson Awaydays 133: He doesn’t know how close he is to getting killed, here and now, right in front of his rugger-bugger prick mates.
2000		Indep. Rev. 4 Jan. 8: The rugger buggers. They gravitate towards jobs with brewery chains.
2002		S. Maloney Something Fishy (2006) 29: Princess Diana denies bonking rugger bugger.
2010		IOL News (Western Cape) 20 Jan. 🌐 He looks the kind of rugger-bugger type.